/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.analysis;

import org.apache.lucene.analysis.TokenStream;

import java.util.Map;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

/**
 * Factory for {@link PatternReplaceFilter}.
 * 
 * <pre class="prettyprint" >
 * &lt;fieldType name="text_ptnreplace" class="solr.TextField" positionIncrementGap="100"&gt;
 *   &lt;analyzer&gt;
 *     &lt;tokenizer class="solr.KeywordTokenizerFactory"/&gt;
 *     &lt;filter class="solr.PatternReplaceFilterFactory" pattern="([^a-z])" replacement=""
 *             replace="all"/&gt;
 *   &lt;/analyzer&gt;
 * &lt;/fieldType&gt;
 * </pre>
 * 
 * @version $Id$
 * @see PatternReplaceFilter
 */
public class PatternReplaceFilterFactory extends BaseTokenFilterFactory {
	Pattern p;
	String replacement;
	boolean all = true;

	@Override
	public void init(Map<String, String> args) {
		super.init(args);
		try {
			p = Pattern.compile(args.get("pattern"));
		} catch (PatternSyntaxException e) {
			throw new RuntimeException(
					"Configuration Error: 'pattern' can not be parsed in "
							+ this.getClass().getName(), e);
		}

		replacement = args.get("replacement");

		String r = args.get("replace");
		if (null != r) {
			if (r.equals("all")) {
				all = true;
			} else {
				if (r.equals("first")) {
					all = false;
				} else {
					throw new RuntimeException(
							"Configuration Error: 'replace' must be 'first' or 'all' in "
									+ this.getClass().getName());
				}
			}
		}

	}

	public PatternReplaceFilter create(TokenStream input) {
		return new PatternReplaceFilter(input, p, replacement, all);
	}
}
